c125 slave unit chart background issue

[Doug Martin]

I have two c125 displays, one is a slave to the master. Both are updated to v16.49. Has worked fine for two years. Now with both units on in chart mode, the slave unit only shows the base map (no Navionics chart detail). The slave unit does display nav data like boat position, speed, TTG, WPTs, log data. I have checked the connections and have done a factory reset on both units. After the reset, the Navionics chart did come up for a few days. After turning on the slave unit today on the fly bridge, only the base map came up again. Also the Sirus weather detail does not show up on the slave unit but works fine on the master. Please help.